score =int(input("请输入成绩:"))
print("计科2011-12-匡鑫")
if score >= 90:
    grade='A'
elif score>=80:
    grade='B'
elif score>=70:
    grade='C'
elif score>=60:
    grade='D'
else:
    grade='E'
print("成绩等级：",grade)
